package cn.edu.sdjzu.xg2121.domain;


public class Pagination {
    public String toLimitClause(int totalNum){
        //向前台提供元组总数( totalNum可以为0)
        this.totalNum = totalNum;
        //偏移量
        int offset =(this.pageNo - 1)* this.pageSize;
        //输出LIMIT子句，注意关键字两端的空格
        return " LIMIT " +offset+ ", " + this.pageSize;
    }
    public Pagination(int pageSize, int pageNo){
        //防止错误赋值
        if(pageSize > 0){
            this.pageSize = pageSize;
        }
        if(pageNo > 0){
            this.pageNo = pageNo;
        }
    }
    //如果没有get方法,fastjson将无法读取对象属性
    public int getPageSize() {
        return pageSize;
    }
    public int getPageNo() {
        return pageNo;
    }
    public int getTotalNum(){
        return totalNum;
    }
    //每页的对象(元组)数
    private int pageSize = 5;
    //页号
    private int pageNo= 1;
    //对象(元组)总数
    public int totalNum= 1;
}
